[PATCH 08/24] KVM: SEV: Don't explicitly pass PSC buffer to snp_begin_psc()

[Paolo Bonzini]

From: Sean Christopherson <seanjc@xxxxxxxxxx>

Stop explicitly passing the PSC buffer to snp_begin_psc(): it *must*
be the scratch area.  This will allow fixing a variety of bugs without
further complicating the code.

No functional change intended.

Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Reviewed-by: Michael Roth <michael.roth@xxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-ID: <20260501202250.2115252-9-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
 arch/x86/kvm/svm/sev.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index a3e85348ace9..8577451b82b2 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3841,7 +3841,7 @@ struct psc_buffer {
 	struct psc_entry entries[];
 } __packed;
 
-static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc);
+static int snp_begin_psc(struct vcpu_svm *svm);
 
 static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret)
 {
@@ -3883,7 +3883,6 @@ static void __snp_complete_one_psc(struct vcpu_svm *svm)
 static int snp_complete_one_psc(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
-	struct psc_buffer *psc = svm->sev_es.ghcb_sa;
 
 	if (vcpu->run->hypercall.ret) {
 		snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
@@ -3893,11 +3892,13 @@ static int snp_complete_one_psc(struct kvm_vcpu *vcpu)
 	__snp_complete_one_psc(svm);
 
 	/* Handle the next range (if any). */
-	return snp_begin_psc(svm, psc);
+	return snp_begin_psc(svm);
 }
 
-static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc)
+static int snp_begin_psc(struct vcpu_svm *svm)
 {
+	struct vcpu_sev_es_state *sev_es = &svm->sev_es;
+	struct psc_buffer *psc = sev_es->ghcb_sa;
 	struct psc_entry *entries = psc->entries;
 	struct kvm_vcpu *vcpu = &svm->vcpu;
 	struct psc_hdr *hdr = &psc->hdr;
@@ -4567,7 +4568,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
 		if (ret)
 			break;
 
-		ret = snp_begin_psc(svm, svm->sev_es.ghcb_sa);
+		ret = snp_begin_psc(svm);
 		break;
 	case SVM_VMGEXIT_AP_CREATION:
 		ret = sev_snp_ap_creation(svm);
-- 
2.54.0